Positive-control electric starter



L. GUILLEMART POSITIVE-CONTROL ELECTRIC STARTER Feb. 24, 1970 7Sheets-Sheet 1 Filed NOV. 15, 1967 Feb. 24, 1970 L. GUILLEMART 3,

POSITIVE-CONTROL ELECTRIC STARTER Filed Nov. 15, 1967 7 Sheets-Sheet 2Feb. 24, 1970 L. GUILLEMART 3,496,787

POSITIVE-CONTROL ELECTRIC STARTER Filed Nov. 15, 1967 7 Sheets-Sheet 5Feb. 24, 1970 GUILLEMART 3,496,737

POSITIVE-CONTROL ELECTRIC STARTER Filed Nov. 15, 1967 '7 Sheets-Sheet 4Feb. 24, 1970 L. GUILLEMART POSITIVE-CONTROL ELECTRIC STARTER 7Sheets-Sheet 5 Filed NOV. 15. 1967 a Q/ NA L. GUILLEMARTPOSITIVE-CONTROL ELECTRIC STARTER Feb. 24, 1970 '7 Sheets-Sheet 6 FiledNOV. 15, 1967 Feb. 24, 1970 GUILLEMART 3,496,

POSITIVE-CONTROL ELECTRIC STARTER Filed Nov. 15, 1967 '7 Sheets-Sheet '7United States Patent 3,496,787 POSITIVE-CONTROL ELECTRIC STARTER LucienGuillemart, Billancourt, France, assignor to Regle Natiouale des UsinesRenault, Billaucourt, and Automobiles Peugeot, Paris, France Filed Nov.15, 1967, Ser. No. 683,323 Claims priority, application France, Dec. 18,1966,

1 89,14 Int. Cl. G05g 5/06; H02k 7/118 US. Cl. 74527 18 Claims ABSTRACTOF THE DISCLOSURE This invention relates to electric starter motors ofthe positive control type, notably for internal combustion engines.

' It is known to use electric starter motors wherein a drive adapted tobe connected to the engine is disengaged therefrom automatically,usually by spring means, when the engine is running, this driveconsisting as a rule of a pinion, a free-wheel device and membersassociated therewith which are adapted to slide in straight or helicalsplines formed in the starter motor shaft. When it is desired to startthe engine, positive control means urge the drive towards the toothedring of the engine fly-wheel until the drive pinion'is in meshingengagement therewith.

This positive control action was formerly actuated by using a pull knobbut nowadays the use of a plunger-core electromagnet or solenoid actingupon a drive fork has become widespread.-

In either case the return spring restores the drive to its initialposition when the engine is-running and the drive is disconnected. 6

Now due to the developments of modern engines, notably their lighterweight and the increment in their rotational speed, more and moreconsiderable vibration is produced and attended by very small relativemovements of the various component elements; now these smalldisplacements of the movable parts, notably of the drive on the splinedarmature shaft, are a source of considerable wear and tear, accompaniedby a degradation of the lubri- "cant (grease), and, moreover, by atendency of the pinion to crawl towards the fly-wheel ring. As a result,the drive tends to compress its return spring balacing the stray drivingforces caused by said vibration.

In certain types of engines and under certain conditions it may happenthat this state of balance is not reached when the drive pinion engagesthe fly-wheel ring; as a consequence, the pinion is milled off veryrapidly, thus requiring a premature reconditioning of the starter motor.

- It is the essential object of the present invention to provide animprovement in or relating to starter drives whereby the above-mentionedinconveniences can be avoided by positively preventing the drive fromreaching the engine toothed fly-wheel. This improvement is characterisedprimarily in that it comprises a device associated with the drivecontrol means, which incorporates mechanical, electro-mechanical orother suitable means for positively retaining the drive in itsinoperative position .by locking or self-locking the whole or part ofthe drive.

ice

According to another feature characterising this invention theafore-mentioned locking action is obtained either by using theelectromagnet of the drive control means or with the assistance of apower member other than said drive control means. 7

Other features of this invention will appear more clearly as thefollowing description proceeds with reference to the accompanyingdrawings illustrating diagrammatically by way of example a few typicalforms of embodiment of this invention. In the drawings:

FIGURE 1 illustrates diagrammatically the more of operation of aconventional starter motor drive;

FIGURE 2 illustrates the core of the control electromagnet and the forkhead after the energizing circuit of the starter motor has been switchedoff;

FIGURE 3 illustrates the relative position of the core strap and of thefork head at the beginning of an engine starting operation;

FIGURE 4 shows a first form of embodiment of the locking deviceaccording to this invention;

FIGURE 5 illustrates another form of embodiment of this device whichprovides a friction action;

FIGURE 6 shows a ditferent form of embodiment providing a self-lockingaction;

FIGURE 7 shows another form of embodiment of the locking means;

FIGURE 8 shows another form of the embodiment using a bell-crank lockingmeans.

FIGURE 9 shows a further form of embodiment providing a self-lockingaction, and

FIGURE 10 is a wiring diagram of the device illustrated in FIGURE 9.

In the conventional starter motor drive arrangement as illustrateddiagrammatically in FIGURE 1 an electromagnet 1 comprises one or a pairof windings 2, 3 adapted to attract a soft-iron core 4. The wiringdiagram of the windings is associated with the wiring diagram of thestarter motor; thus, the winding 3 is connected to the circuit of theseries-wound motor 5 of the starter motor; a storage battery 6 providesenergizing current for the pair of windings 3, 3 via a starter switch 7and for the motor directly through the main switch 8 responsive to saidcore 4. When switch 7 is closed, both windings 2 and 3 are energized andthus attract the core 11, whereby the latter, by means of the cross-pin9 carried by its end strap 10, carries along the head of the fork '4 bycausing the latter to pivot about its fulcrum pin 12. The fork r11 thuspositively controls in turn the movement of the drive (not shown)towards the fly-wheel ring by meansof shoes, clamps, studs or likemember 13. Then the starter motor is energized under a reduced voltageuntil the core 4 closes switch 8 (as shown in FIGURE 1), thusshort-circuiting coil 3 and causing the motor starter '5 to operateunder maximum power conditions. When the engine begins to fire, switch 7is re-opened and the pair of windings 2 and 3 are de-energized. s

The reaction produced by the helical splines of the armature shaft onthe starter drive keep the latter in meshing engagement with thefly-wheel ring if the engine does not start; now if some cut-out playwere not provided, the fork action would prevent any opening of the mainswitch 8.

This cut-out play I, which may be obtained in various ways, isillustrated diagrammatically in FIGUREZ in the form of a lost motion ofpin 9 in the strap of plunger-core 4 in relation to the two arms 14 and15 of the U-shaped head of fork 11. The current is cut out in the mainswitch 8 when the cross pin 9 is caused to engage the front arm 14 bythe return spring 16 (also visible in FIGURE 4), the drive being in itsoperative position in this case. As the return spring keeps urging thecore 4 backward during thelastiraction. of its stroke, t i e-4..meve efork at 9' against the rear arm 15 of the U-shaped fork head so thatthis fork begins to rotate as shown in FIGURE 3. It is this lost-motionstroke which is utilized according to this invention forproviding asimple yet eflicient and economical solution to the problem of lockingand releasing the starter drive. I

According to a first form of embodiment of this'inven- ,frictionalengagementthus produced betweenthethrust pin 9 of said strap 10 and thefront face 28' of the fork head facilitates this locking action. Theroller 20 also acts as a guide member tothe core strap 10 when it isattracted by the electromagnet '17.

In a third form of embodiment illustrated in FIGURE 6 a frictionlessself-locking action is obtained by providing'in the strap 10 of core. 4an elongated hole 29 having its major axis directedvertically andadapted to receive 10 freely therein the pivot pins 19 and 19' of; apair of superposed rollers 20 and 20 respectively. The bottom roller 20engages with its lower portion the upper face 30 'of fork 11 forming anacuate angle a with the longitudinal axis of this fork, and providedwith an upward protien, as shown in FIGURE the strap 1 of o e 4 f 15jection 31. On the other hand this bottom rOller electromagnet 17 hasformed therein elongated holes 18 engages the ,top roller 20"" f hi hthe':uppe1 portion having their major dimension directed a g t a g s tcontacts an adjustment tapered portion 32 of a set screw the core axisA-B; rotatably mounted'in these elongated 33 engaging a tapped holeformed in the end cover 34 holes 18 is the Pivot Pt!-1 19 of a roller 20constituting of the starter motor, this screw being locked in the setthe .thrust member'controlling the movements of fork 11 20 position by anut 34. A straight cam face may be suband therefore the starter drive21; therefore, these holes stituted for the tapered portion of saidscrew. 18 permit a slight vertical free motion of roller 20. D to thaction e d b h return spring 15 When the Winding 2 0f gnet 17 is detherollers 20 and 20 rolling on each other will ensure a energized and thedrive resumes its inoperative position firm, i.e. playless locking ofthe drive fork 11. Any movedue to the action of the return spring 16 ofthe electrot f h d i e h i 21 d h fl h l magnet, the roller 20 engages abearing face 23 ach e ring will tend to pivot the lever-forming fork 11in the th the Starter Cover and Parallel to the aXiS O translationclockwise direction and therefore to rotate the rollers of Cote Thecontour of the bottom 25 0f the 20 and 20 in opposite directions,whereby the top roller U-shaped fork head is so designed that it causesthe roller 20 will t nd to move up the taper 32 and the bottom 20 to beurged against Said bearing face 23 When h roller 20 will tend to move upthe inclined plane 30 in fork tends to Pivot about its Pivot P 12 as aconseorder to reinforce the locking or wedging action. When quence ofthe effort exerted by the starter drive 21 which th rel is caused by theattraction-of plunger core 4 is transmitted through the P y 26 t0 theShoes 13 O by coil 22 the rollers 20, 20' will roll equally on the saidfork 11. In this case, the drive 21 is locked against i li d plane 30 offork 11 d on h dju tment taper motion. 32

This locking'action is released when the core 4 is at- According to afourth form, of embodiment illustrated ttacted y the Winding as aconseqllehee 0f the in FIGURE 7 of the drawings the locking action isengagement of roller 20 fromseid bearing face w .produced by means of aseparate strap 35 shown in secfact, when the roller 20 leaves thebearing face 23 it can tion, The core 4 is connected 5 this strap bymeans of a move freely in a Vertical Plane due to the Provision of thepin 36 movable in an elongated hole and adapted to slide elongated holesThus, the fork 11 can Pivot e y in a tubular portion 37 of the strap.The front end of When the roller 20 has reached the front face 27 0f thethis tubular portion comprises notches 38 and the afore- U- P forkheadsaid pin 36 isv adapted to engage the bottom of these Conversely,when the energizing current has been cut notches When the core 4 isattracted by the coil 22. 7 out in the electromagnet coil and themagnetic field .Radial holes 39 formed in the tubular portion 37 are hasthus been removed, the return movement is controlled adapted to receiveballs 40 which in the inoperative. posiby the return spring 16 after acut-off stroke. Thus, roller tion of said core and fork 4, 11 engage afixed cam face 20 engages the rear face 28 of the U-shaped head of fork41 formed in an inner annular groove or cavity 42. The 11, d ubs u ntlmoves the drive 21 to its inoperative core 4 is formed at its front endwith a movable cam face position. At the end of its stroke," the roller20 is re- 43 enabling the balls 40 to be disengaged from said fixedinserted between the bearing plane 23 of the starter cover cam face 41when the core is attracted. The strap 35 com- 24 and the inner face 25of the U-shaped fork head. p ses at one end a cross pin 9 adapted topush the strap The arrangement illustrated in FIGURE 4 is of the on thefork 11 and at the core end another cross pin locking type without anyself-locking action, for in the 44 whereby the core 4 can push the strap35. inoperative position the bottom 25 of the fork head is sub- When thedrive 21 exerts an. eifort'on the fork 11 by stantially parallel to theplane of said bearing face 23 means of p l y 16 d Shoes 13, and assumingthat h and thus the plays likely to exist or develop in the various fork11 is in its inoperative position, the core 4, by holdmechanicalconnections are not taken up. ing theballs 40 in their outermostposition, will lock the In a modified form of embodiment of thisinvention strap 35 and ttherefore the fork, since these balls engagewhich is illustrated diagramatically in FIGURE 5, the the externalgroove or cavity 42 and are urged against from hearing face 28' of theU-shaped head of fork 11 the cam face 41 thereof. is inclined in theinoperative position, with respect to the According to a fifth form ofembodiment shown in axis of translation of core 4, so that if an effortF is FIGURE 8, a bell-crank lever 45 fulcrumed at 46 interexerted on thepulley 26 of drive 21, the force exerted by connects the electromagnetcore 4 and the fork 11.-To this the return spring 16 against the core 4and transmitted end, this fork comprises two slideways 47, 48 betweenthrough the pin '9 of strap 10 creates a'thrust applied to which thepush member 49 carried by the strap-shaped said fork 11 which tends totake up the plays of pulley end of the outer arm of lever 45 is adaptedto move. The 26 on drive 21, of shoes 13 on said pulley 26, and of forkother arm of lever 45 has formed therein another pair of =11 on itspivot pin 12. Under these conditions the fork slideways 50 and 51receiving therebeween the push mem- 11 is locked by the engagement ofstrap 10 of core 4 her or pin 9 of the strap-shaped portion 10 of core4. against a roller20 rigid with the cover 24 of the starter By properlycalculating-the angle 3 (of approximately case, the inclination of therear face 28 of said fork 90) formed by the slideway 47 of fork 11.andthe having an angular value so calculated that the reaction straightline connecting the axis of the thrust pin 49 of produced on the pivotpin 9 of strap 10 is sufficient to said bell-crank lever 45 and itsfulcrum 46, ,it is possicause this strap 10 to be locked against saidroller. The ble in the inoperative position of the fork to obtain aknee-action locking this fork as a consequence of the efforts exerted bythe drive 21 on the shoes 13 of .said fork. I

On the other hand, when'the core 4 is attracted by the coil 22 thethrust pin 49 of bell-crank lever 45 causes the fork 11 to pivot about.its fulcrum pin 12. Due to the specific kinematic arrangement resultingfrom the disposition of pins 9, 46 and 49, and also to the, properlyselected value of the angle of inclination of slideway 48, the pullproduced by com 4 during tthe initial portion of its stroke can bemultiplied or increased, this pull being on the other hand reducedduring the last portion of this stroke, which is particularlyadvantageous considering the law governing the coercitive force ofelectromagnets.

A last exemplary form of embodiment of this invention is illustrated inFIGURE 9. In this modified structure the locking action is produced byusing an auxiliary electromagnet having its coil 52 secured to anintermediate bearing 53 of the armature shaft 54 and adapted to holdtthe drive 21 in its inoperative position by exerting a magnetic pullthereon.

As shown in the wiring diagram of FIGURE 10, the winding 52 of thisauxiliary electromagnet is not energized when the combination ignitionand starting switch 55 is open (position or in the ignition and startingposition shown in dash lines in the figure (position D), in whichposition the coils 2 and 3 of the control electromagnet are energized toattract the core 4 controlling in turn the main starter switch 5. Thecoil 52 is energized only when the aforesaid combination switch 55 is inits ignition position (position A).

To avoid a too fierce braking of the starter motor by the auxiliaryelectromagnet when the switch 55 is moved from its start position to itsignition position, and when the starter rotates at a relatively highspeed, a rotary contact 56 for example of the centrifugal or frictiontype is inserted if desired in the circuit of coil 52.

Of course the present invention should not be construed as being limitedby the specific forms of embodiment described hereinabove andillustrated in the attached drawings, since other modifications andvariations may be brought thereto without departing from the spirit andscope of the invention as set forth in the appended claims.

What is claimed is:

1. A positive-control electric starter for an internal combustionengine, comprising: a shiftable drive device associated with a rotatingshaft of the armature of an electric starter motor; pivotable shiftlever means one end of which engages said drive device and the other endof which is fork-shaped; electromagnet means for controlling said drivedevice, said electromagnet means being energized through a starterswitch; a core member forming a part of said electromagnet means andassociated with the fork-shaped end of said shift lever means; resilientmeans for urging said core into its inoperative position; and lockingmeans associated with said core and with the fork-shaped end of saidshift lever means for positively restraining the shift lever meansagainst rotation and thereby positively locking said drive device in itsinoperative position when said core is in its inoperative position.

2. A positive-control electric starter according to claim 1, wherein thelocking means is an electromagnet and is constituted by saidelectromagnet controlling said drive device, the core of saidelectromagnet being adapted to lock positively, by mechanical means,said drive device when said electromagnet is not energized.

3. A positive-control electric starter according to claim 1, whereinsaid locking means is an auxiliary electromagnet having a coil securedto an intermediate bearing of said motor armature shaft and adapted,when energized, to exert a magnetic pull on said shiftable drive devicein order to hold it in its inoperative position.

4, A positive-control electric starter according to claim 2, wherein oneend of said core member is strap-shaped and is provided with anelongated slot having its major axis disposed at right angles to theaxis of said core member, and further comprising a roller carried onsaid strap-shaped end and having a pivot pin adapted to revolve in saidelongated slot, the roller contacting, in the inoperative position ofsaid starter, a U-shaped head of the fork-shaped end of said shift leverand further contacting a fixed flat face extending parallel to the axisof said core member.

5. A positive-control electric starter according to claim 2, wherein theend of said core member is strap-shaped, a thrust transmitting cross-pinis carried by said strap, the fork-shaped end of said shift lever isU-shaped and has an inner front face inclined in its inoperativeposition with respect to the axis of said core member, said front faceconstituting a bearing surface of said cross-pin when said shift leveris in inoperative position.

6-. A positive-control electric starter according to claim 5, furthercomprising a roller having a fixed pivot pin, and wherein the upper faceof said strap-shaped end of the core member is adapted to bear againstsaid roller for guiding said strap face, during its translation and forlocking said strap by the reaction of the fork-shaped end of said shiftlever against said cross-pin.

7. A positive-control electric starter according to claim 2, wherein oneend of said core member is strap-shaped, is provided with an elongatedslot having its major axis directed vertically and adapted to receivefreely therein the pivot pins of a pair of vertical tangentiallysuperimposed rollers in rolling engagement with each other.

8. A positive-control electric starter according to claim 7, wherein thefork-shaped end of said shift lever has a face which forms an angle withthe longitudinal center line of the shift lever and is engaged by thelower of said rollers in the inoperative position of said shift lever.

9. A positive-control electric starter according to claim 7, wherein anadjustment taper having an end screwed in the end cover of said startermotor is engaged by the upper of said rollers in the inoperativeposition of said shift lever.

10. A positive-control electric starter according to claim 7, wherein astraight cam face is rigid with the end cover of said starter motor andis engaged by the upper of said rollers in the inoperative position ofsaid shift lever.

11. A positive-control electric starter according to claim 2, whereinsaid core member is adapted to slide in a tubular portion of a separatesliding strap inserted between said core member and the fork-shaped endof said shift lever, said strap being provided with a first crosspinreceiving the thrust of said core member, and a second cross-pin engagedin the fork-shaped end of said shift lever to transmit said thrust.

12. A positive-control electric starter according to claim 11, whereinsaid separate strap is provided in said tubular portion with recessesadapted to receive balls and with notches on the side nearest the shiftlever.

13. A positive-control electric starter according to claim 12, whereinfixed cavities having a cam face are adapted to partly house said balls,said cam face constituting an abutment therefor.

14. A positive-control electric starter according to claim 12, whereinsaid core member is formed with a cam face and its end comprises across-pin, said balls being able to be released by said cam when saidcore member is attracted, and said cross-pin being adapted to engage thebottom of said notches of the separate strap.

15. A positive-control electric starter according to claim 2, whereinsaid core member has a strap-shaped head with a thrust pin moved betweentwo slideways of one arm of a bell-crank lever fulcrumed on a fixedpivot pin and interposed between said strap, and saidshift lever.

' 16. A positive-control electric starter according to claim 15, whereinsaid bell-crank lever has on its other arm a strap-shaped portioncarrying a thrust pin and said shift lever has two slideways formed onits end, said pin being movable in said slideways causing said bellcranklever to pivot about said fixed pin;

17. A -positive-control electric starter according to claim 3, whereinsaid auxiliary electromagnet is fed through the combination of a starterand ignition switch of the engine only in the ignition position thereof.

18. A positive-control electric starter according to claim 17, wherein acentrifugal friction or like rotational switch is inserted in theenergizing circuit of said auxiliary electromagnet in .order to preventsame from becoming v 8 energized in case the starter motor speed wereabnormally high. 1 a v.

References Cited 1v UNITED STATES PATENTS 2,909,940 Dawkins 74 5 27 10/1959' 3,156,125 11/1964 Straub a 74-126 3,177,728 4/1965 Fariso n 310-833,223,863 12/1965 Preece er a1. 310 75 3,359,440' 12/1967 West 310-83FRED c. MATTERN', ]R., Primary Examiner I WESLEY s. RATLIFF, JR.,Assistant Examiner US. Cl; X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,496,787 Dated February 24. 1970 Inventor(s) Lucien GUILLEMART It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In the Title, change the priority date of "Dec. 18, 1966" to Dec. 28,1966 SIGNED AND SFAI. E SE? 15197'0 Attest:

mm! 1:. sum, M. Fletcher, I1- com s f fatgntg Attesting Officer

